Method of Mixture.
When the body and the water are in thermal equilibrium, the
final temperature T° of the mixture is taken. Then, the heat
lost by the body divides itself between the water and the
Heat lost by body = Heat gained by water & casing,
weight x sp. ht. x fall of temp. = weights x sp. hts. x rise of temp.
ws (/• - T°) - (wl s} -f wfy) (T - /!>,
where w wl and w^ are the weights in Ibs., and s sl and J2 the
specific heats of the body, the water, and the casing respectively :
jj being unity. The value w% s% is known as the * water equivalent'
of the vessel. The first temperature of the water is // while f is
that of the body after steaming; and the changes are shewn
graphically at A, Fig. 598. Inserting known values, that of
s may be found, the following table being obtained by this and
SPECIFIC HEATS OF VARIOUS SUBSTANCES.
Water at 39 'i°
... I '00
Water at 212°
Ice at 32°
Steam at 212*
Air ... ...